The protests had been dubbed the Great March of Return, in support of the declared right of Palestinian refugees to return to land they or their ancestors fled from or were forced to leave in the war which followed Israel’s founding in 1948.

The Israeli government, which has long ruled out a mass return of Palestinians, said terrorists wanted to use the protests as cover to cross into its territory and carry out attacks.

‘Wilful killings’

Mr Zeid told the emergency session on Gaza that the “stark contrast in casualties on both sides is… suggestive of a wholly disproportionate response” by Israel.

An Israeli soldier was “reportedly wounded, slightly, by a stone” on Monday, he said, while 43 Palestinians were killed at the site of the protests. Seventeen more Palestinians were killed away from what he called the “hot spots”.

Image copyrightEPA

Image caption
Israel and the Palestinians have blamed each other for the deaths

He said there had been “little evidence of any [Israeli] attempt to minimise casualties”. Israel’s actions might, he said, “constitute ‘wilful killings’ – a grave breach of the Fourth Geneva Convention”, an international law designed to protect civilians under occupation.

Mr Zeid said he supported a call for an “international, independent and impartial” investigation into the violence in Gaza, adding that “those responsible for violations must in the end be held accountable”.

“The occupation must end,” he said, “so the people of Palestine can be liberated, and the people of Israel liberated from it.

“End the occupation, and the violence and insecurity will largely disappear.”

Israel occupied Gaza in the 1967 Middle East war. Although it withdrew its forces and settlers in 2005, the UN still considers the territory occupied because Israel retains control over the territory’s air space, coastal waters and shared border.

Tens of thousands of Palestinians have held weekly protests at the border in the lead-up to the 15 May anniversary of the mass displacement of Palestinians from land which became Israel in the war which followed Israel’s founding in 1948.

While most Palestinians have demonstrated at a distance from the heavily guarded fence, Israel said its soldiers only used lethal force against people carrying out “terrorist activity and not on demonstrators”.